Motor vehicles generally have a plurality of openings in the body, which are closed by panes of glass, to be precise sometimes with movably guided panes, which in many cases are coupled to a drive, and sometimes with fixedly installed panes. Known among the fixedly installable panes are those which have a peripheral frame of plastic which is permanently bonded to the pane in the border region of the inner side of the pane and along the border of the pane, for example as disclosed in European Patent Publication No. 304 694. This frame is molded directly onto the pane by using an adhesion promoter. The frame has sealing elements in the form of peripheral ribs of small cross-sectional width, which during installation of the pane come to bear against the border regions of the body opening. For securing the pane in the body opening, the frame also has cross-sectionally hook-shaped retaining elements.
The retaining elements have a web which runs normally with respect to the pane and, at the end of the web, a hook with a locking face running parallel to the pane and to the body part and with a ramp face facing away from the locking face. When the pane is brought to bear against the body opening, the retaining elements are bent to the side on account of the ramp face at the end until, upon further pressing into place of the pane, the hook end of the retaining elements snaps in behind the body part and its locking face bears against the body part and secures the pane.
In the case of a frame of a plastic of relatively low dimensional stability, the retaining elements are formed by inserts of a plastic of relatively great dimensional stability, which are arranged on the frame, distributed at intervals in the circumferential direction. During production of the frame they are initially placed into the compression mold for the frame, as is the pane itself, so that a foot provided on them is molded around by the material of the frame and the retaining elements are thereby permanently bonded to the frame and to the pane. In the case of a frame of a plastic of relatively great dimensional stability, the retaining elements are produced in one piece with the other profile parts of the frame. Then, however, there is provided on the frame a peripheral groove for receiving a peripheral soft seal, which has to be additionally inserted during installation of the pane.
In the case of the first-mentioned embodiment of the known pane, the installation is admittedly relatively simple. However, it makes production relatively complex, because the inserts have to be produced separately and have to be inserted individually into the compression mold for the frame. As a result, the compression mold is also very complicated and its handling is laborious. In addition, the pane is not very burglarproof, because the webs with the hook ends can be bent away from the body part relatively easily by a thin tool pushed in through the relatively soft material of the frame and then the pane can be freely lifted out altogether. In the case of the last-mentioned embodiment of the known pane, production is admittedly simplified. However, due to the fact that the frame consists in its entirety of a material of relatively high dimensional stability, the pliancy of the frame is less, so that a soft seal has to be additionally inserted, not only for reasons of good sealing, but also due to the requirement that the frame should interact with the body without any clearance. This restricts the permissible production tolerances both in the case of the window frame and in the case of the body and also requires additional installation measures. In spite of the relatively high dimensional stability of the frame, such a window pane is not much more burglarproof because, due to the greater dimensional stability of the material of the frame, in this case adequate flexibility of the web with the hook end has to be achieved by a corresponding reduction in the wall thickness of the web and/or by the locking face being shortened. Both of these make it easier for the hook ends to be pushed away.